/*
Copyright (c) 2008  Franklin Schmidt <fschmidt@gmail.com>

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/

package fschmidt.util.java;

import java.util.Calendar;
import java.util.Date;


public class DateUtils {
	private DateUtils() {}  // never

	public static Date roundToDay(Date date) {
		Calendar cal = Calendar.getInstance();
		cal.setLenient(false);
		cal.setTime(date);
		Calendar cal2 = Calendar.getInstance();
		cal2.setLenient(false);
		cal2.clear();
		cal2.set(cal.get(Calendar.YEAR),cal.get(Calendar.MONTH),cal.get(Calendar.DATE));
		return cal2.getTime();
	}

	public static Date add(Date date,int days,int unit) {
		Calendar cal = Calendar.getInstance();
		cal.setLenient(false);
		cal.setTime(date);
		cal.add(unit,days);
		return cal.getTime();
	}

	public static Date addDays(Date date,int days) {
		return add(date,days,Calendar.DATE);
	}

	public static Date addHours(Date date,int hours) {
		return add(date,hours,Calendar.HOUR);
	}

	private static final long millisPerHour = 1000L*60L*60L;
	private static final long millisPerDay = millisPerHour*24L;
	
	public static int daysBetween(Date dateFrom,Date dateTo) {
		long from = dateFrom.getTime();
		long to = dateTo.getTime();
		long diff = (to - from)/millisPerDay;
		return (int)diff;
	}

	public static int datesBetween(Date dateFrom,Date dateTo) {
		long from = roundToDay(dateFrom).getTime();
		long to = roundToDay(dateTo).getTime();
		long diff = (to - from + millisPerHour)/millisPerDay;
		return (int)diff;
	}

	public static Date max(Date date1,Date date2) {
		return date1.after(date2) ? date1 : date2;
	}

	public static Date min(Date date1,Date date2) {
		return date1.before(date2) ? date1 : date2;
	}

	public static boolean equalToTheSecond(Date date1,Date date2) {
		return date1!=null && date2!=null && date1.getTime()/1000 == date2.getTime()/1000;
	}


	public static void main(String[] args) {
		Date today = roundToDay(new Date());
		Date date = today;
		for( int i=0; i<10; i++ ) {
			System.out.println(daysBetween(today,date));
			date = addDays(date,1);
		}
	}
}
